geddylee2112 Messages: 5 Registered: July 2012 Location: Montréal
Junior Member
Hello im selling my Kustom kit ! its the kustom 250 head and the 2 matching cabs 3x15 jbl , one as the power amp in and the other is a straight 3x15 i want 1200$ for it . Im at Montréal québec . thanks!
Without knowing the model # of the JBL's it's hard to say what the impedance would be individual for each speaker. . .standing alone. . .let alone
what the over-all value would be with all six. Also there's several different ways they could be wired. . .also Kustom put booster amps in some of
the 250 series bringing the power to 500 watts. The head itself puts out 250 watts probably optimized to 4 or 8ohm loads. . .four ohm load being max output
at 250 W. As you increase the load impedance. . .the power goes down. . .ohms law! You're right though about the danger at less than 4 ohms. That could over-heat the
power transistors and cause failure. . .again though. . .without knowing the ohms rating of the JBL's you're poking' in the dark. If this is a factory released rig, then I'm sure
the speaker compliment has been optimized. Judging from the schematics of these rigs that I've seen, I'd say there was some advanced brain power lurking in Chanute Kansas
back in the day. . .
stevem Messages: 4733 Registered: June 2004 Location: NY
Senior Member
In any 3 speaker cabinet that Kustom ever made be it 3-12" or 3-15" they used 16 ohm speakers in parallel for a total impeadance of 5.3 ohms .
The K250 heads and the cabinet power modules are made to output there max power into a 4 ohm load and 5.3 ohms is fine.
All Kustom amps from 100 watts on up and from the B series on have a thermal circuit breaker in them that turns the amp off the the output stage gets above the danger level of 182 degrees F as what might take place if you where playing the amp loud hooked up to a impeadance that was too low.
pleat Messages: 1452 Registered: June 2004 Location: Belding, Mi
Senior Member
Stevenm is correct in Kustom using 16 ohm speakers in the K100, K200 and K400 series amps.
I have a Kustom chart that says that in the slant metal face amps Kustom used 8 ohm speakers wired in parallel for a 2.7 ohm load. In the K250/500 series.
pleat Messages: 1452 Registered: June 2004 Location: Belding, Mi
Senior Member
Yes, one the K250 series, the washer on the speaker jack states 3ohms-4ohms. The Slant face K150 series still used 16 ohm speakers for a 8 ohm load to the head.